Generally, detergents are used to remove different soils corresponding to hard surfaces such as bathrooms, kitchens and floors and therefore those having compositions suitable to each of these hard surfaces are used. For instance, as detergents for kitchen facilities, those containing surfactants, solvents, alkali agents and the like are used in order to remove oily soils denatured by the actions of heat, sunlight, oxygen in the atmosphere and the like. Also, as detergents for bathrooms, detergents containing surfactants, solvents, metal ion sequestering agents and the like are used to remove soils such as sebum, metal soaps, particularly, calcium salts of fatty acids. Many technologies have been developed so far.
It has been also known that excellent detergency is obtained by compounding a polyol type compound having an alkyl or alkylene chain in these detergents. As the polyol compound, alkyl glyceryl ether type compounds, saccharide type compounds such as alkyl glycosides and fatty acid ester type compounds of (poly) glycerol are known. For example, with regard to alkyl glyceryl ether type compound, a liquid detergent using a monoalkyl monoglyceryl ether having 5 or less carbon atoms in the alkyl group is described in the publication of JP-A No. 7-3289. It is described in Japanese Patent Application National Publication (Laid-Open) No. 7-500861 that a glyceryl ether of an alkyl group having 12 to 18 carbon atoms wherein 50 mol % or more of the glycerol ether is di-isomers is contained and compounds such as high-molecular hydrocarbons such as a paraffin, fatty acid esters, fatty acid esters of monohydric alcohols and aliphatic C18 to C40 ketones may be contained as a non-surfactant foaming resistant agents though these compounds are optional components. Liquid detergents exhibiting more excellent detergency by using a mixture consisting of a combination of monoalkyl monoglyceryl ethers having 1 to 11 carbon atoms in the alkyl group and differing in the number of carbon atoms or a combination of isomer alkyls among these ethers are described in the publication of JP-A No. 11-189796. In the publication of JP-A No. 11-256200, there are descriptions concerning a liquid detergent composition containing a monoglycerol ether derivative having any one of an alkyl group having 1 to 12 carbon atoms, an alkenyl group, a benzyl group or a phenyl group, a terpene type hydrocarbon, a surfactant and a builder. As to other liquid detergent compositions containing a glyceryl ether derivative, there are descriptions concerning a liquid detergent composition which is formulated with a monoalkyl monoglyceryl ether having a methyl-branched alkyl group and exhibits excellent detergency effected on oily stains and sebum soils in JP-A No. 57-133200, and concerning a detergent containing a monoalkyl (mono, di or tri)glyceryl ether having 8 to 16 carbon atoms in the publication of U.S. Pat. No. 4,430,237. Also, examples of detergents containing a polyol compound represented by the formula containing a glycerol ether derivative may include detergents disclosed in each publication of U.S. Pat. No. 3,427,248, JP-A No. 64-67235 and JP-W No. 5-502687.
As detergents containing an alkyl glycoside type compound, liquid detergents containing an alkyl glycoside type surfactant, a monoterpene or sesquiterpene type hydrocarbon and other components are described in each publication of JP-A Nos. 2-182793, 2-32197 and 3-269097.
In the meantime, as technologies concerning a liquid detergent using a hydrophobic organic solvent, those described in the publication of JP-A No. 2-29498 besides the aforementioned liquid detergents compounded with a terpene type hydrocarbon may be exemplified. A liquid detergent composition containing 0.01 to 1.0% by weight of an anionic surfactant, 0.01 to 1.0% by weight of terpene or sesquiterpene type hydrocarbon solvent and 0.001 to 0.1% by weight of water-soluble divalent metal is described in this publication. It is to be noted that hydrocarbons such as paraffin is compounded as a foam resistant agent and it is described in the publication of the aforementioned JP-W No. 7-500861 that these hydrocarbons may be compounded as optional components.
However, a part of current polyol type compounds is one exhibiting excellent detergency effected on denatured oily stains and the like, but are highly soluble in water and therefore, only insufficient effect is obtained in the case of detergents having a large water content. Although there is also an idea that the concentration of a solvent is increased, not only an economical problem arise but also sticky feeling remains, requiring wiping with water for finishing.
On the other hand, current liquid detergents using a hydrophobic organic solvent are stabilized by incorporating the hydrophobic organic solvent into the micelle of a surfactant, namely, by forming an o/w emulsion to obtain a uniform and stable liquid and therefore satisfactory detergency cannot be obtained. This is considered to be because the surfactant surrounds the hydrophobic organic solvent with the lipophilic group being positioned inside and the hydrophilic group being positioned outside, thereby confining the hydrophobic organic solvent. Therefore, one which is brought into contact with soils when cleaning is the solvent confined in the micelle of the surfactant. For this, the effect that the solvent originally has can be exhibited insufficiently.
In view of this, there is an idea that the amount of a water-insoluble solvent to be compounded is increased to make a w/o emulsion. For example, a liquid detergent containing orange oil as its major component has been already known. However, when the amount of the hydrophobic organic solvent is increased, this is undesirable not only from an economical problem but also from the viewpoint of safety in generally domestic uses in the case of using a flammable hydrophobic organic solvent such as hydrocarbon solvents. If a hydrophobic organic solvent having low volatility is used, however, not only the solvent is a cause of sticky feeling after used but also it is difficult to wipe the solvent because it cannot be wiped with water.
It is disclosed in the publication of JP-A No. 6-306400 that a near three-critical point composition constituted of (1) an amphipathic solvent such as triethylene glycol monohexyl ether, (2) a non-polar solvent or less-polar solvent such as a hydrocarbon and (3) a polar solvent such as water is used as a detergent. However, a system containing a large amount of a compound such as triethylene glycol monohexyl ether and diethylene glycol butyl ether used for the example of the technique in the publication in which the number of hydroxyl groups is only one cannot exhibit sufficient detergency.
Also, in the publication of JP-A No. 2002-20791, a liquid detergent forming a bicontinuous phase is disclosed. However, the polarity of a hydrophobic component to be used is high and therefore only insufficient detergency can be obtained.